A nanotwinned-alloy strategy enables fast sodium deposition dynamics

Sodium metal batteries are promising for energy storage due to their low cost and high energy density, but they suffer from slow sodium dynamics that lead to dendrite growth and poor cycling performance. A new strategy using nanotwinned alloys, created by high-pressure solid solution and Joule-heating treatment, enhances sodium dynamics and promotes homogeneous sodium deposition. The nanotwinned alloy collector delivers impressive long-term plating/stripping stability exhibiting stability for 5300 h at 5 mA cm−2 under 5 mA h cm−2 and a cumulative capacity of 13.25 Ah cm−2.

• 1
  High-pressure solid solution extends Si solubility in Al, forming nanotwinned-Si particles through Joule-heating treatment.
• 2
  Sodiophilic nanotwinned-Si sites exhibit a high diffusion rate, transitioning deposition behavior from diffusion-controlled to reaction-controlled, facilitating spherical Na deposition and dendrite-free growth.
• 3
  HPJH-AlSi alloy collector demonstrates long-term plating/stripping stability, achieving 5300 h at 5 mA cm−2 with a cumulative capacity of 13.25 Ah cm−2.